JEE Main 2025 (Online) 23rd January Morning Shift | JEE Main Year Wise Previous Years Questions

JEE Main 2025 (Online) 23rd January Morning Shift

MCQ (Single Correct Answer)

-1

Which of the following happens when $\mathrm{NH}_4 \mathrm{OH}$ is added gradually to the solution containing 1 M $\mathrm{A}^{2+}$ and $1 \mathrm{M} \mathrm{B}^{3+}$ ions?

Given : $\mathrm{K}_{\text {sp }}\left[\mathrm{A}(\mathrm{OH})_2\right]=9 \times 10^{-10}$ and $\mathrm{K}_{\mathrm{sp}}\left[\mathrm{B}(\mathrm{OH})_3\right]=27 \times 10^{-18}$ at 298 K.

$\mathrm{A}(\mathrm{OH})_2$ will precipitate before $\mathrm{B}(\mathrm{OH})_3$

$\mathrm{A}(\mathrm{OH})_2$ and $\mathrm{B}(\mathrm{OH})_3$ will precipitate together

Both $\mathrm{A}(\mathrm{OH})_2$ and $\mathrm{B}(\mathrm{OH})_3$ do not show precipitation with $\mathrm{NH}_4 \mathrm{OH}$

$\mathrm{B}(\mathrm{OH})_3$ will precipitate before $\mathrm{A}(\mathrm{OH})_2$

JEE Main 2025 (Online) 23rd January Morning Shift

MCQ (Single Correct Answer)

-1

Ice at $-5^{\circ} \mathrm{C}$ is heated to become vapor with temperature of $110^{\circ} \mathrm{C}$ at atmospheric pressure. The entropy change associated with this process can be obtained from

$\int_{268 \mathrm{~K}}^{273 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\mathrm{m}} \text {, fusion }}{\mathrm{T}_{\mathrm{f}}}+\frac{\Delta \mathrm{H}_{\mathrm{m}, \text { vaporisation }}}{\mathrm{T}_{\mathrm{b}}}+\int_{273 \mathrm{~K}}^{373 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}+\int_{373 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}$

$\int_{268 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\text {melting }}}{273}+\frac{\Delta \mathrm{H}_{\text {boiling }}}{373}$

$\int_{268 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}} \mathrm{dT}+\frac{\mathrm{q}_{\text {rev }}}{\mathrm{T}}$

$\int_{268 \mathrm{~K}}^{273 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{m}}}{\mathrm{T}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\mathrm{m}}, \text { fusion }}{\mathrm{T}_{\mathrm{f}}}+\frac{\Delta \mathrm{H}_{\mathrm{m}, \text { vaporisation }}^{373 \mathrm{~K}}}{\mathrm{~T}_{\mathrm{b}}}+\int_{273 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}}{T}+\int_{373 \mathrm{~K}}^{383 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}}{\mathrm{T}}$

JEE Main 2025 (Online) 23rd January Morning Shift

MCQ (Single Correct Answer)

-1

Match the List - I with List - II

	List - I Name reaction		List - II Product obtainable
(A)	Swarts reaction	(I)	Ethyl benzene
(B)	Sandmeyer's reaction	(II)	Ethyl iodide
(C)	Wurtz Fittig reaction	(III)	Cyanobenzene
(D)	Finkelstein reaction	(IV)	Ethyl fluoride

Choose the correct answer from the options given below:

A-II, B-III, C-I, D-IV

A-II, B-I, C-III, D-IV

A-IV, B-I, C-III, D-II

A-IV, B-III, C-I, D-II

JEE Main 2025 (Online) 23rd January Morning Shift

MCQ (Single Correct Answer)

-1

The element that does not belong to the same period of the remaining elements (modern periodic table) is:

Platinum

Osmium

Iridium

Palladium

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